Summary
The FAA proposes to adopt a new airworthiness directive (AD) for certain Bombardier Model DHC-8-100 (as described above), DHC-8-200, and DHC-8-300 series airplanes. This proposed AD would require doing a one-time inspection for damage of the electrical cable harness assembly located on the left and right wing root to fuselage aft seal, and repair if necessary; and reworking the fuselage aft seal assembly (left and right) to create a clearance between the electrical cable assemblies and the edge of the fairing panel. This proposed AD results from a report that an airplane encountered an uncommanded propeller feathering during climb, which resulted in an emergency landing. We are proposing this AD to prevent chafing or grounding of the wiring against the aft seal assemblies, which, if not corrected, could interrupt the operation of various systems, including the propeller feather control, alternating current (AC) electrical power, and standby hydraulic power, and result in reduced controllability of the airplane.